Aplidium minithorax, Monniot, Françoise, 2012

Monniot, Françoise, 2012, Some ascidians from the southern coast of Madagascar collected during the “ AtimoVatae ” survey, Zootaxa 3197, pp. 1-42 : 11-12

publication ID

https://doi.org/ 10.5281/zenodo.246182

DOI

https://doi.org/10.5281/zenodo.4893760

persistent identifier

https://treatment.plazi.org/id/3055E11F-FF9A-FF9A-71A5-CDD3FE116991

treatment provided by

Plazi

scientific name

Aplidium minithorax
status

sp. nov.

Aplidium minithorax n. sp.

( Figures 8 View FIGURE 8 , 9A View FIGURE 9. A )

Stations. TR 7 (MNHN: A1 APL.B 545). TA 25 (MNHN: A1 APL.B 56). TA 29 (MNHN: A1 1PL.B 544, type).

The holotype is about 20cm large, made of several coalescent and more or less flattened lobes ( Fig. 9A View FIGURE 9. A ). The tunic is entirely filled with sand, hard, and does not let see the zooid arrangement. The zooids remain orange in formalin, densely packed, perpendicular to the colony surface. They reach 1cm in length but are contracted ( Fig. 8 View FIGURE 8 A). The oral aperture has 8 short lobes. A tridentate languet starts from the anterior rim of the atrial siphon ( Fig. 8 View FIGURE 8 B). There are 5 to 6 longitudinal muscle fibres on each side of the thorax. The branchial sac ( Fig. 8 View FIGURE 8 C) is short with 5 rows of stigmata and 10 to 12 stigmata in a half row, they are difficult to count according to the contraction. The stomach wall has 5 deep folds ( Fig. 8 View FIGURE 8 B). The post-abdomen is longer than the thorax plus the abdomen ( Fig. 8 View FIGURE 8 A). The ovary takes place at a short distance from the abdomen and is followed by one or two rows of few testis vesicles limited to the anterior half of the post-abdomen. A single larva is incubated in the thorax ( Fig. 8 View FIGURE 8 D). The trunk measures 550 to 650µm, circled by a tail in one turn. The 3 adhesive papillae are separated by odd ramified vesicles. A crescent of dense, very small vesicles lies on each side of the adhesive papillae.

A minithorax n. sp. has in common with A. mernooensis ( Brewin, 1956) the 8 oral lobes, the branchial sac and the stomach. It differs by the colony shape, made of circular lobes of a single system in the New Zealand species.

Another Aplidium species with 5 rows of stigmata: A. petrense ( Michaelsen, 1919) is recorded from Zanzibar, Mozambique ( Millar, 1956) and Madagascar ( Vasseur, 1970), but the colonies are devoid of sand and the stomach wall has numerous folds.

Kingdom

Animalia

Phylum

Chordata

Class

Ascidiacea

Order

Enterogona

Family

Polyclinidae

Genus

Aplidium

Loc

Aplidium minithorax

Monniot, Françoise 2012
2012
Loc

A. mernooensis (

Brewin 1956
1956
Loc

A. petrense (

Michaelsen 1919
1919
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